<!DOCTYPE html>
<html>
<head>
  <title>Big Buck Test</title>
  <meta name=viewport content='width=device-width initial-scale=1.0'>
</head>
<body>
  <video controls id=video src=bigbuck.webm></video>
  <button id=fullscreen>fullscreen</button>
  <iframe id=iframe></iframe>
</body>
<script>
  document.getElementById('fullscreen').addEventListener('click', _ => {
    document.getElementById('video').webkitRequestFullscreen();
  });

  if ('HTMLPortalElement' in self) {
    let portal = document.createElement('portal');
    portal.src = "picture-in-picture/iframe-content.html";
    document.body.appendChild(portal);
  }
</script>
</html>
